In LTE (Long Term Evolution), priority control is performed in such a manner that a bearer (LCH: Logical Channel) is established for each QCI (QoS Class Identifier) and a priority (Logical Channel Priority) is assigned to each bearer.
Here, data sets in the same bearer are deemed to have the same priority. In addition, the priority control is performed both in a radio base station eNB and a mobile station UE.
Further, in LTE, the MAC layer is in charge of priority control in a radio access network. For example, as illustrated in FIG. 7, the MAC layer of a radio base station eNB is configured to decide the order of data sets to be transmitted to a radio bearer, based on priorities assigned to respective bearers.
Meanwhile, in LTE Release 12, a study on avoiding radio access network congestion due to U-plane signals is made in the “UPCON (U-Plane Congestion Management) WI (Working Item).”
Lately, services provided even on the same web browser are a mixture of texts, images, motion videos, streaming media, and the like.
Under the above circumstances, if radio access network congestion occurs, there is a demand to transmit streaming media, texts, images, motion videos in this order, for example.
In the present situation, in order to carry out QoS (Quality of Service) control, priority control over an EPS (Enhanced Packet System) bearer is performed using QCIs.
In addition to a QCI, the “UPCON WI” defines a “FPI (Flow Priority Indicator)” indicating the priority of each data flow (IP flow) for more detailed priority control, and discusses solving means for (a scheduler of) the radio base station eNB to carryout the QoS control and priority control using the FPI.